DPS: Cellular tracking devices don't monitor specific data

Minnesota Department of Public Safety Commissioner Mona Dohman has assured lawmakers that a controversial device that tracks cell phone users does not have the ability to monitor specific data like voice calls, text messages or e-mails.

“This technology has been vitally important in our efforts to locate people quickly, mitigate further criminal actions and save lives.” Dohman wrote in the letter to a bipartisan group of four lawmakers from the House and Senate.

They wrote Dohman last month expressing concern about “cellular exploitation devices” marketed under names like the Kingfish and Stingray, which mimic local phone towers to capture data and location information of cellular phones in a given area. The Minnesota Bureau of Criminal Apprehension has one; so does the Hennepin County Sheriff’s Office. A local FBI official declined to say whether the agency has one, and the U.S. marshals’ office didn’t respond to an inquiry.

The letter, signed by The letter, signed by Sens. Scott Dibble, DFL-Minneapolis, and Sean Nienow, R-Cambridge, and Reps. John Lesch, DFL-St. Paul, and Mary Liz Holberg, R-Lakeville, precedes a House Civil Law Committee hearing later this month where law enforcement will likely be questioned about the devices. They asked what kind is used, its cost, capabilities and whether a warrant is required to use it. The letter also demands examples of closed investigations where the equipment was used and “why it was felt to be necessary.” The growing concern over surveillance technology was echoed this week after the International Association of Chiefs of Police took steps to establish policy regarding its use of such equipment.

Dohman said the Department owns one Stingray II and one Kingfish, used exclusively by the BCA. Since 2005 the department has spent $632,773 on the devices.

Instead of a search warrant, a less-stringent court order is obtained “in the vast majority of cases” when the technology is used. A court order is bypassed in some cases involving the threat of imminent harm such as abductions.

The devices use identification data similar to a serial number to track a “target telephone” and don’t observe or follow other phones on the network.

“NO data is permanently retained in association with this equipment.” Dohman wrote. “Data are continuously overwritten as the equipment is used to search for a subsequent target phone number.
Cases where it has been used included locating a missing person, finding a burglary suspect in a case where multiple guns were stolen, tracking a 14-year-old girl at risk of sexual abuse, and tracking murder suspect who killed a woman in her home. He was ultimately convicted. In the latter case, “it is unlikely the suspect would have been identified using more traditional investigative techniques.” Dohman wrote.